P any of baltimoee city



(No Model.) f y Y G. W. HlCK-.MAN 81.1. RMGCOY.

INGANDBSGENT 'PILAMENT FOR E1.1JGTRJ.'G LAMPS.

No. 302,134.` Patented' .1u-1y 15, 1884'.

WI TJV' ESSES Y C. N. PETERS. Pmln-lwgnnbor, Washington. D

UNrrnn ST1-Vriesi PATENT OFFICE.

eEoneE/wjnrcxMAN, onwAsHrNeroN, D. c., AND Josnrn F. MCcoY, on

nAHwAY, N. J., AssreNons r ro .THE vrAnuor MANUFACTURING coM- rANY-OF BALTIMoRE o1TY,oF`BALTIMonE, M. D.l

f INCANDESCENT FILAMENT `Fon ELECTRIC LAMPS.

SPEQIFICATON forming part of Letters Patent No. 302,134, dated July 15, 1884.

Application led November 7, 1883. (No model.)

To all whom it may concer-n,.-

Be it known that we, GEO. W. HIOKMAN, of Washington, Districtfof Columbia, and J- snrn F. MCCOY, of Rahway, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Car-` bon Filaments for Electric Lamps; and we do hereby declare that the following is a full, clear, and exact description of the invention, 1o which will enable others skilled in the art to which it appertains to makeand use the same, reference bein ghad to the accompanying drawings and tothe letters of reference marked thereon, which form part of this specication. Our invention relates to an improvement in incandescing carbon, laments and-the mode of manufacturing the same, the object of the improvement being to produce a very .durable and flexible carbon lament, which may 2o receive and retain any desired shape, and

have sufficient strength to maintain itself intact in any position and under any jarring or vibration to which a lamp is liable to be subjected while in use, either stationary or upon vehicles or vessels of travel. 1

Although by the carbonization of. various substancesf-such as paper, parchment, hair, silk and cotton threads, bers of hemp, bamboo, and others-incandes'cing laments have 3o been obtained having proper electrical qualities combined with sufficient strength for use in stationary lamps, and in shapes not involving a very great extent or length of lament between its end supports, there is still a de- 3 5 sire to obtain a carbon lament which will endure the strains incident to travel, and which may be given gracefull shapes and sufficient length to give extensive illumination without requiring multplicationof laments in a single lamp, and consequent weakening of the electric current by division. In our experiments, with a View to the production of a carbon lament having the desired qualities, as stated, we have found-that the woody-ber of the stems of the dock-weed,

when properly treated, yields a carbon whichv seems to leave nothing to be desired in this Y line. In treating these stems we remove the l bark,- and pith, and cut the wood rst into proper length, and then split it into narrow 5o pieces, which we shave down to the desired size, which may reach even to the small dia1neter of a` ne 'hair with a length of several inches, so great is the toughness of the ber. The pieces thus preparedpwe steep in dilute alcohol, (say equal quantities of proofspirit and water,) and nd that a wonderful change in their condition is thus caused, the ber becoming so pliable that it may be wound or coiled into greatly-involved shapes with ease and safety from breakage.v While the ber is thus pliable we give it the desired'shape, preferably by bending it about a refractory mold, and after securing the ends we dip the mold and ber into melted pure parafne, and then Yplace them into a crucible and subject the same to the necessary heat for carbonizing'the l ber, It seems that the parafne causes a kind of concentrationin the mass of ber while carbonization is progressing, and replaces in the pores all expelled volatile matters, so that a compact, strong, and resilient lament of carbon is the result. v

In the drawing is shown'an incandescent electric lamp having an .incandescing carbon 7 5 lament prepared according to our invention. The lament F has a central stem, f, about which is coiled a helix, h, connected to the stem integrally, one endl of the helix and one end of thecentral stem being att-ached to the leading in wires. We believe that such a shape could not be given to a carbon lament made by any other process and from any other substance heretofore used, the diameter being suiciently small toV oppose a proper resistance to the current, and the strength after carbonization being such that the lament'will support itself in all positions and resist all strains from` jarring to which a lamp is ever likely to be subjected.

The berof the dock-weed stem contains gum, resin, sugar, starch, and oil, all of which are soluble, or'partly soluble, in alcohol; and it would appear that any vegetable stem having these substances in its woody ber will, with similar treatment, give a carbon lament affine, and finally earbonizing, substantially as set forth. In testimony that We claim the foregoing as our own We allix om1 signatures in presence o' I5 two Witnesses.

GEO. W. HIGKMAN. JOSEPH F. MCooY.

Titnessesz B. F. MORSELL, EDWARD E. ELLIS. 

